Operational Amplifier MOSFET 4-20mA – Circuit for Converting 0-5V to 4-20mA Current Source

4-20mamosfetoperational-amplifier

basically is want to make a circuit that takes 0-5v input and converts it in and corresponding output current of 4-20mA using opamp , i have seen reference circuit from this pdf https://www.analog.com/media/en/technical-documentation/technical-articles/D61_EN-Convert.pdf
but it has converted from 1-5v to 4-20mA current source
but i want to make a circuit that converts 0-5 to 4-20mA current source

Best Answer

You can always just use your reference circuit (1-5V input) and convert your 0-5V input to 1-5V with two resistors:

schematic

simulate this circuit – Schematic created using CircuitLab

If you don't have a +5V rail, you can create an equivalent from any higher rail with a pair of resistors and a little math:

schematic

simulate this circuit